Use "formal definitions" to show that: $$ \begin{array}{1} 2 n^{4}+n-1000=\Omega\left(n^{3} ight) W n^{2}-5 n+200=0\left(n^{3} ight) 3 n^{3}+5 n-900=\theta\left(n^{3} ight) \end{array} $$ Show your work, similar to the examples from the notes. Using limits or another method will receive no credit. Each expression is worth $7 \mathrm{pts}$ for a total of $21 \mathrm{pts}$. CS.VS. 1177||